Identification of the threadlike structures in the rat abdominal subcutaneous tissue using Hemacolor staining. ((a), (b), and (c)) Appearance of the subcutaneous area after serial applications of three Hemacolor solutions: Solution 1 (methanol fixative, (a)), Solution 2 (eosin stain, (b)), and Solution 3 (methylene blue stain, (c)). Dotted line is the abdominal middle line. (d) Appearance of the subcutaneous area after wash-out of Hemacolor solutions. Note the dark blue threadlike structures (arrows). See the Materials and Methods sections for a description of the protocol.